Vacancies tailoring lattice anharmonicity of Zintl-type thermoelectrics.

While phonon anharmonicity affects lattice thermal conductivity intrinsically and is difficult to be modified, controllable lattice defects routinely function only by scattering phonons extrinsically. Here, through a comprehensive study of crystal structure and lattice dynamics of Zintl-type Sr(Cu,Ag,Zn)Sb thermoelectric compounds using neutron scattering techniques and theoretical simulations, we show that the role of vacancies in suppressing lattice thermal conductivity could extend beyond defect scattering. The vacancies in Sr2ZnSb2 significantly enhance lattice anharmonicity, causing a giant softening and broadening of the entire phonon spectrum and, together with defect scattering, leading to a ~ 86% decrease in the maximum lattice thermal conductivity compared to SrCuSb. We show that this huge lattice change arises from charge density reconstruction, which undermines both interlayer and intralayer atomic bonding strength in the hierarchical structure. These microscopic insights demonstrate a promise of artificially tailoring phonon anharmonicity through lattice defect engineering to manipulate lattice thermal conductivity in the design of energy conversion materials.

Giant magnetocaloric effect in spin supersolid candidate Na2BaCo(PO4)2.

Supersolid, an exotic quantum state of matter that consists of particles forming an incompressible solid structure while simultaneously showing superfluidity of zero viscosity1, is one of the long-standing pursuits in fundamental research2,3. Although the initial report of 4He supersolid turned out to be an artefact4, this intriguing quantum matter has inspired enthusiastic investigations into ultracold quantum gases5-8. Nevertheless, the realization of supersolidity in condensed matter remains elusive. Here we find evidence for a quantum magnetic analogue of supersolid-the spin supersolid-in the recently synthesized triangular-lattice antiferromagnet Na2BaCo(PO4)2 (ref. 9). Notably, a giant magnetocaloric effect related to the spin supersolidity is observed in the demagnetization cooling process, manifesting itself as two prominent valley-like regimes, with the lowest temperature attaining below 100 mK. Not only is there an experimentally determined series of critical fields but the demagnetization cooling profile also shows excellent agreement with the theoretical simulations with an easy-axis Heisenberg model. Neutron diffractions also successfully locate the proposed spin supersolid phases by revealing the coexistence of three-sublattice spin solid order and interlayer incommensurability indicative of the spin superfluidity. Thus, our results reveal a strong entropic effect of the spin supersolid phase in a frustrated quantum magnet and open up a viable and promising avenue for applications in sub-kelvin refrigeration, especially in the context of persistent concerns about helium shortages10,11.

Stability of peri-implantitis surgical reconstructive therapy-a (> 2 years) follow-up of a randomized clinical trial.

OBJECTIVES: This follow-up study aimed to report the 24- and 30-month outcomes of a cohort previously enrolled in a randomized clinical trial on surgical reconstructive treatment of peri-implantitis. METHODS: Twenty-four patients were diagnosed with peri-implantitis and treated with surgical reconstructive therapy with or without the adjunctive use of Er:YAG laser. Within-group and between-group comparisons were tested with mixed model with repeated measures. RESULTS: Regarding peri-implant pocket depth (PPD) reduction (control vs. laser test group) between 6 months (- 1.85 vs. - 2.65 mm) and 30 months (- 1.84 vs. - 3.04 mm), the laser group showed statistically significant changes but not the control group. In terms of radiographic marginal bone loss (RMBL) at 6 months (- 1.1 vs. - 1.46 mm) to 24 months (- 1.96 vs. - 2.82 mm), both groups showed statistical difference compared to baseline. The six explanted implants all were featured by severe peri-implantitis and mostly with no or limited keratinized tissue (< 2 mm) at baseline and membrane exposure after surgery. Among the 15 retained cases, eight cases achieved more than 50% peri-implant bone level gain. CONCLUSIONS: Within the limitation and follow-up time frame of this trial, the outcome of the surgical reconstructive therapy sustained or improved in most of the cases. However, 25% of the implants with severe peri-implantitis failed 2 years after the surgical reconstructive therapy. The use of Er:YAG laser favors PPD reduction in the longer term up to 30 months. CLINICAL RELEVANCE: Longer-term follow-up on reconstructive therapy of peri-implantitis revealed sustained or improved stability in certain cases, but the survival of implants with severe peri-implantitis has its limitation, especially when there is limited keratinized tissue (< 2 mm or no KT). TRIAL REGISTRATION: Clinical Trials Registration Number: NCT03127228 and HUM00160290.

EVIDENCE SUPPORTS SHORT-TERM CLINICAL BENEFITS OF ADJUNCTIVE ORAL PROBIOTICS FOLLOWING SCALING AND ROOT PLANING TREATMENT.

ARTICLE TITLE AND BIBLIOGRAPHIC INFORMATION: Hu D, Zhong T, Dai Q. Clinical efficacy of probiotics as an adjunctive therapy to scaling and root planning in the management of periodontitis: a systematic review and meta-analysis of randomized controlled trails. J Evid Based Dent Pract. 2021;21(2):101547. doi:10.1016/j.jebdp.2021.101547. SOURCE OF FUNDING: Self-funded. TYPE OF STUDY/DESIGN: Systematic review with meta-analysis of data.

RECONSTRUCTIVE THERAPY OF PERI­IMPLANTITIS, COMPARED TO RESECTIVE INTERVENTION, MAY RESULT IN LESS PERI­IMPLANT MUCOSAL RECESSION.

ARTICLE TITLE AND BIBLIOGRAPHIC INFORMATION: Sanz-Martín I, Cha J-K, Sanz-Sánchez I, Figuero E, Herrera D, Sanz M. Changes in peri­implant soft tissue levels following surgical treatment of peri­implantitis: a systematic review and meta-analysis. Clin Oral Implants Res. 2021;32(suppl 21):230-244. https://doi.org/10.1111/clr.13840. SOURCE OF FUNDING: No financial support. TYPE OF STUDY/DESIGN: Systematic review with meta-analysis.

Interplanar Ferromagnetism Enhanced Ultrawide Zero Thermal Expansion in Kagome Cubic Intermetallic (Zr,Nb)Fe2.

A cubic metal exhibiting zero thermal expansion (ZTE) over a wide temperature window demonstrates significant applications in a broad range of advanced technologies but is extremely rare in nature. Here, enabled by high-temperature synthesis, we realize tunable thermal expansion via magnetic doping in the class of kagome cubic (Fd-3m) intermetallic (Zr,Nb)Fe2. A remarkably isotropic ZTE is achieved with a negligible coefficient of thermal expansion (+0.47 × 10-6 K-1) from 4 to 425 K, almost wider than most ZTE in metals available. A combined in situ magnetization, neutron powder diffraction, and hyperfine Mössbauer spectrum analysis reveals that interplanar ferromagnetic ordering contributes to a large magnetic compensation for normal lattice contraction upon cooling. Trace Fe-doping introduces extra magnetic exchange interactions that distinctly enhance the ferromagnetism and magnetic ordering temperature, thus engendering such an ultrawide ZTE. This work presents a promising ZTE in kagome metallic materials.

Maresin: Macrophage Mediator for Resolving Inflammation and Bridging Tissue Regeneration-A System-Based Preclinical Systematic Review.

Maresins are lipid mediators derived from omega-3 fatty acids with anti-inflammatory and pro-resolving properties, capable of promoting tissue regeneration and potentially serving as a therapeutic agent for chronic inflammatory diseases. The aim of this review was to systematically investigate preclinical and clinical studies on maresin to inform translational research. Two independent reviewers performed comprehensive searches with the term "Maresin (NOT) Review" on PubMed. A total of 137 studies were included and categorized into 11 human organ systems. Data pertinent to clinical translation were specifically extracted, including delivery methods, optimal dose response, and specific functional efficacy. Maresins generally exhibit efficacy in treating inflammatory diseases, attenuating inflammation, protecting organs, and promoting tissue regeneration, mostly in rodent preclinical models. The nervous system has the highest number of original studies (n = 25), followed by the cardiovascular system, digestive system, and respiratory system, each having the second highest number of studies (n = 18) in the field. Most studies considered systemic delivery with an optimal dose response for mouse animal models ranging from 4 to 25 µg/kg or 2 to 200 ng via intraperitoneal or intravenous injection respectively, whereas human in vitro studies ranged between 1 and 10 nM. Although there has been no human interventional clinical trial yet, the levels of MaR1 in human tissue fluid can potentially serve as biomarkers, including salivary samples for predicting the occurrence of cardiovascular diseases and periodontal diseases; plasma and synovial fluid levels of MaR1 can be associated with treatment response and defining pathotypes of rheumatoid arthritis. Maresins exhibit great potency in resolving disease inflammation and bridging tissue regeneration in preclinical models, and future translational development is warranted.

Revisiting best practice guidelines and patient care workflow for managing the risk of medication-related osteonecrosis of the jaw: comparative summary and case studies.

OBJECTIVE: Patients taking antiresorptive medications in dental clinics are at risk of medication-related osteonecrosis of the jaw (MRONJ), which poses daily challenges for their clinicians. This paper aimed to summarize and revisit the three most recognized practice guidelines for the management and prevention of MRONJ, which were proposed by the American Association of Oral and Maxillofacial Surgeons (AAOMS), and presented by the Journal of Bone and Mineral Research (JBMR) and the Journal of Clinical Oncology (JCO). Results and case studies: The AAOMS position paper focused on risk stratification by different medications, management decision trees, risk factors, pathophysiology, and disease staging. The JBMR international consensus presented eight focused questions, which were addressed by systematic reviews. The JCO clinical practice guideline presented six clinical questions, and each concluded with practical recommendations. Practical information was summarized and converted into an adoptable patient care workflow for clinicians to follow and apply in daily practice. Three case studies presented were treated following these guidelines. Each patient underwent advanced surgeries including alveoloplasty, tooth extraction, implant placement, and particulate bone grafting. Some of the considerations not fully informed were discussed and illustrated in each step of the patient care workflow, which included specifics for risk communication, updates on the use of antibiotics, biomarkers, and drug holidays. CONCLUSION AND PRACTICAL IMPLICATIONS: Structured risk communication with official informed consent documentation should be considered before initiating invasive treatments. Disease control phase with home care therapy should be provided prior to staged reconstructive therapy. Drug holidays and antibiotics coverage can be customized based on individual conditions and related procedures with interprofessional coordination.

Effect of laser-assisted reconstructive surgical therapy of peri-implantitis on protein biomarkers and bacterial load.

OBJECTIVES: This randomized clinical trial assessed changes in protein biomarker levels and bacterial profiles after surgical reconstructive therapy of peri-implantitis and investigated whether the adjunctive use of Er:YAG laser impacts protein biomarker and microbial outcomes. MATERIALS AND METHODS: Twenty-four patients received surgical reconstructive therapy for peri-implantitis with guided bone regeneration following mechanical debridement with (test) or without (control) the adjunctive irradiation of Er:YAG laser. Bacterial and peri-implant crevicular fluid (PICF) samples were collected over 6 months and analyzed with bacterial qPCR and luminex multiplex assays. RESULTS: Surgical reconstructive treatment significantly affected the concentration of PICF protein biomarkers, including a 50% reduction in IL-1ß between 2 and 4 weeks (p < .0001). Both MMP-9 (p < .001) and VEGF (p < .05) levels steadily decreased after treatment. In the laser group, the peak increase in IL-1ß was attenuated at 2 weeks, followed by significant reduction in MMP-9 (p < .01) and VEGF (p < .05) across all follow-up appointments compared with the control nonlaser group. The total bacterial load was reduced 2 weeks after treatment, especially in the laser group, but recolonized to presurgical levels after 4 weeks in both groups (p < .01). The composition of selective pathogens varied significantly over the follow-up, but recolonization patterns did not differ between groups. CONCLUSIONS: Reconstructive therapy of peri-implantitis significantly altered PICF protein biomarker and microbial levels during the healing process. The adjunctive use of Er:YAG laser significantly modulated the inflammatory response through reduced levels of MMP-9 and VEGF during the postsurgical period. The bacterial load was reduced immediately after therapy, but recolonization was observed by 4 weeks in both groups.

A colossal barocaloric effect induced by the creation of a high-pressure phase.

As a promising environment-friendly alternative to current vapor-compression refrigeration, solid-state refrigeration based on the barocaloric effect has been attracting worldwide attention. Generally, both phases in which a barocaloric effect occurs are present at ambient pressure. Here, instead, we demonstrate that KPF6 exhibits a colossal barocaloric effect due to the creation of a high-pressure rhombohedral phase. The phase diagram is constructed based on pressure-dependent calorimetric, Raman scattering, and neutron diffraction measurements. The present study is expected to provide an alternative routine to colossal barocaloric effects through the creation of a high-pressure phase.

Triangular Magnet Emergent from Noncentrosymmetric Sr0.94Mn0.86Te1.14O6 Single Crystals.

We report the successful growth of high-quality single crystals of Sr0.94Mn0.86Te1.14O6 (SMTO) using a self-flux method. The structural, electronic, and magnetic properties of SMTO are investigated by neutron powder diffraction (NPD), single-crystal X-ray diffraction (SCXRD), thermodynamic, and nuclear magnetic resonance techniques in conjunction with density functional theory calculations. NPD unambiguously determined octahedral (trigonal antiprismatic) coordination for all cations with the chiral space group P312 (no. 149), which is further confirmed by SCXRD data. The Mn and Te elements occupy distinct Wyckoff sites, and minor anti-site defects were observed in both sites. X-ray photoelectron spectroscopy reveals the existence of mixed valence states of Mn in SMTO. The magnetic susceptibility and specific heat data evidence a weak antiferromagnetic order at TN = 6.6 K. The estimated Curie-Weiss temperature θCW = -21 K indicates antiferromagnetic interaction between Mn ions. Furthermore, both the magnetic entropy and the 125Te nuclear spin-lattice relaxation rate showcase that short-range spin correlations persist well above the Néel temperature. Our work demonstrates that Sr0.94(2)Mn0.86(3)Te1.14(3)O6 single crystals realize a noncentrosymmetric triangular antiferromagnet.

A Seawater-Corrosion-Resistant and Isotropic Zero Thermal Expansion (Zr,Ta)(Fe,Co)2 Alloy.

Zero thermal expansion (ZTE) alloys as dimensionally stable materials are usually challenged by harsh environmental erosion, since ZTE and corrosion resistance are generally mutually exclusive. Here, a high-performance alloy, Zr0.8 Ta0.2 Fe1.7 Co0.3 , is reported, that shows isotropic ZTE behavior (αl  = 0.21(2) × 10-6 K-1 ) in a wide temperature range of 5-360 K, high corrosion resistance in a seawater-like solution compared with classic Invar and stainless Invar, and excellent cyclic thermal and structural stabilities. Such stabilities are attributed to the cubic symmetry, the controllable magnetic order, and the spontaneously formed passive film with Ta and Zr chemical modifications. The results are evidenced by X-ray/neutron diffraction, microscopy, spectroscopy, and electrochemistry investigations. Such multiple stabilities have the potential to broaden the robust applications of ZTE alloys, especially in marine services.

Prognostic factors associated with implant loss, disease progression or favorable outcomes after peri-implantitis surgical therapy.

BACKGROUND: The treatment of the peri-implantitis remains complex and challenging with no consensus on which is the best treatment approach. PURPOSE: To examine the key local and systemic factors associated with implant loss, disease progression, or favorable outcomes after surgical peri-implantitis therapy. MATERIALS AND METHODS: Records of patients treated for peri-implantitis were screened. Patient-, implant- and surgery-related variables on and prior to the day of the surgery were collected (T0: time of peri-implantitis treatment). If the treated implant was still in function when the data was collected, the patient invited to participate for a recall study visit (T1, longest follow-up after treatment). Impacts of the variables on the implant survival, success, and peri-implant bone change after treatment were investigated. RESULTS: Eighty patients with 121 implants with a mean follow-up of 42.6 ± 26.3 months were included. A total of 22 implants (18.2%) were removed during the follow-up period. When relative bone loss (%) was in range 25%-50%, risk for implant removal increased 15 times compared to lower bone loss <25% (OR = 15.2; CI: 2.06-112.7; p = 0.008). Similarly, relative bone loss of >50% increased 20 times the risk of implant failure compared to the <25% (OR = 20.2; CI: 2.42-169.6; p = 0.006). For post-treatment success rate, history of periodontitis significantly increased the risk of unsuccess treatment (OR = 3.07; p = 0.04) after resective surgery). CONCLUSION: Severe bone loss (>50%) poses significantly higher risk of treatment failure.

Non-conventional superconductivity in magnetic In and Sn nanoparticles.

We report on experimental evidence of non-conversional pairing in In and Sn nanoparticle assemblies. Spontaneous magnetizations are observed, through extremely weak-field magnetization and neutron-diffraction measurements, to develop when the nanoparticles enter the superconducting state. The superconducting transition temperature TC shifts to a noticeably higher temperature when an external magnetic field or magnetic Ni nanoparticles are introduced into the vicinity of the superconducting In or Sn nanoparticles. There is a critical magnetic field and a critical Ni composition that must be reached before the magnetic environment will suppress the superconductivity. The observations may be understood when assuming development of spin-parallel superconducting pairs on the surfaces and spin-antiparallel superconducting pairs in the core of the nanoparticles.

Intra- and Interexaminer Repeatability of Diagnostic Peri-Implant Clinical Measurement: A Pilot Study.

Despite the crucial role of examiner reliability on quality research and practice, there is still limited literature analyzing factors affecting examiner variability of peri-implant clinical measurements. The present study investigated clinical peri-implant parameters to quantify their repeatability and investigate factors that may affect their accuracy. Thirty-three implants were examined by 4 operators. Peri-implant probing depth (PD), recession (REC), and gingival index (GI) were measured for agreement and included in the analysis. Agreement was quantified using intraclass correlation coefficients (ICCs; 95% confidence interval); mixed linear and logistic regressions were used to assess additional variables. The overall interexaminer agreement was comparable between PD (0.80) and REC (0.78) but significantly worse for GI (0.45; P < .001). Similarly, the intraexaminer agreement was similar for PD (0.81) and REC (0.80) but significantly worse for GI (0.57; P < .05). The magnitude of PD did not influence the agreement. In contrast, increasing disagreement was noted for positive REC (odds ratio [OR]: 3.0), negative REC (OR: 4.8), and lower GI (OR: 4.4). The incidence of bleeding on probing and severity of GI increased for deeper PD (0.113-unit increase per millimeter). Negative and positive values of recession and lower GI were associated with increasing disagreement. Radiographic bone loss, restoration contour, and implant diameter did not affect PD accuracy in this study. In conclusion, within the limitations of the study, GI measurements presented higher variability than PD and REC did. The PD and GI were associated with one another and increased after multiple measurements.

Experimental Observation of Long-Range Magnetic Order in Icosahedral Quasicrystals.

Quasicrystals (QCs), first discovered in 1984, generally do not exhibit long-range magnetic order. Here, we report on long-range magnetic order in the real icosahedral quasicrystals (i QCs) Au-Ga-Gd and Au-Ga-Tb. The Au65Ga20Gd15 i QC exhibits a ferromagnetic transition at TC = 23 K, manifested as a sharp anomaly in both magnetic susceptibility and specific heat measurements, along with an appearance of magnetic Bragg peak below TC. This is the first observation of long-range magnetic order in a real quasicrystal, in contrast to the spin-glass-like behaviors observed for the other magnetic quasicrystals found to date. Moreover, when Gd is replaced by Tb, i.e., for the Au65Ga20Tb15 i QC, a ferromagnetic behavior is still retained with TC = 16 K. Although the sharp anomaly in the specific heat observed for the Au65Ga20Gd15 i QC becomes broadened upon Tb substitution, neutron diffraction experiments clearly show marked development of magnetic Bragg peaks just below TC, indicating long-range magnetic order for the Au65Ga20Tb15 i QC also. Our findings can contribute to the further investigation of exotic magnetic orders formed on real quasiperiodic lattices with unprecedented highest global symmetry, i.e., icosahedral symmetry.

Striping of orbital-order with charge-disorder in optimally doped manganites.

The phase diagrams of LaMnO3 perovskites have been intensely studied due to the colossal magnetoresistance (CMR) exhibited by compositions around the [Formula: see text] doping level. However, phase segregation between ferromagnetic (FM) metallic and antiferromagnetic (AFM) insulating states, which itself is believed to be responsible for the colossal change in resistance under applied magnetic field, has prevented an atomistic-level understanding of the orbital ordered (OO) state at this doping level. Here, through the detailed crystallographic analysis of the phase diagram of a prototype system (AMn[Formula: see text]Mn[Formula: see text]O12), we show that the superposition of two distinct lattice modes gives rise to a striping of OO Jahn-Teller active Mn3+ and charge disordered (CD) Mn3.5+ layers in a 1:3 ratio. This superposition only gives a cancellation of the Jahn-Teller-like displacements at the critical doping level. This striping of CD Mn3.5+ with Mn3+ provides a natural mechanism though which long range OO can melt, giving way to a conducting state.

Ultrawide Temperature Range Super-Invar Behavior of R_{2}(Fe,Co)_{17} Materials (R = Rare Earth).

Super Invar (SIV), i.e., zero thermal expansion of metallic materials underpinned by magnetic ordering, is of great practical merit for a wide range of high precision engineering. However, the relatively narrow temperature window of SIV in most materials restricts its potential applications in many critical fields. Here, we demonstrate the controlled design of thermal expansion in a family of R_{2}(Fe,Co)_{17} materials (R=rare Earth). We find that adjusting the Fe-Co content tunes the thermal expansion behavior and its optimization leads to a record-wide SIV with good cyclic stability from 3-461 K, almost twice the range of currently known SIV. In situ neutron diffraction, Mössbauer spectra and first-principles calculations reveal the 3d bonding state transition of the Fe-sublattice favors extra lattice stress upon magnetic ordering. On the other hand, Co content induces a dramatic enhancement of the internal molecular field, which can be manipulated to achieve "ultrawide" SIV over broad temperature, composition and magnetic field windows. These findings pave the way for exploiting thermal-expansion-control engineering and related functional materials.

Zero Thermal Expansion and Strong Covalent Binding of VB2 Compound.

Zero thermal expansion (ZTE) is an intriguing phenomenon by virtue of its peculiar lack of expansion and contraction with temperature. The achievement of ZTE in a metallic material is a desired but challenging task. Here we report the ZTE behavior of a single-phase metallic VB2 compound, stacking with the V and B atomic layers along the c direction (αV = 2.18 × 10-6 K-1, 5-150 K). Neutron powder diffraction demonstrates that the ZTE behavior is entangled in the direct blocking of the lattice expansion along all crystallographic directions with temperature. X-ray photoelectron spectroscopy and density functional theory calculations indicate that strong covalent binding adheres the nearest-neighbor B-B and V-B pairs, which is proposed to control the ZTE within both the basal plane and the c direction. An intimate correlation is revealed between the covalent binding and the lattice parameters. Our work indicates the opportunity to design metallic ZTE with strong chemical binding in the future.